policy: integrate policy settings to RPC API

Author: txhsl

eth/api_backend.go

@@ -25,11 +25,13 @@ import (
 	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/common"
+	cmath "github.com/ethereum/go-ethereum/common/math"
 	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/bloombits"
 	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/core/systemcontracts"
 	"github.com/ethereum/go-ethereum/core/txpool"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
@@ -363,7 +365,16 @@ func (b *EthAPIBackend) SyncProgress() ethereum.SyncProgress {
 }
 
 func (b *EthAPIBackend) SuggestGasTipCap(ctx context.Context) (*big.Int, error) {
-	return b.gpo.SuggestTipCap(ctx)
+	suggestTipCap, err := b.gpo.SuggestTipCap(ctx)
+	if err != nil {
+		return nil, err
+	}
+	stateDb, _, err := b.StateAndHeaderByNumber(ctx, rpc.LatestBlockNumber)
+	if err != nil {
+		return nil, err
+	}
+	minGasTipCap := stateDb.GetState(systemcontracts.PolicyProxyHash, systemcontracts.GetMinGasTipCapStateHash()).Big()
+	return cmath.BigMax(suggestTipCap, minGasTipCap), nil
 }
 
 func (b *EthAPIBackend) FeeHistory(ctx context.Context, blockCount uint64, lastBlock rpc.BlockNumber, rewardPercentiles []float64) (firstBlock *big.Int, reward [][]*big.Int, baseFee []*big.Int, gasUsedRatio []float64, err error) {